One or more longitudinal rows of photophores on ventral surface of body, photophores present or absent on isthmus, posterior orbital photophore absent. Bony pectoral radials 4 in most, one in Cyclothone.

Small fishes, from 2 cm to about 36 cm, usually less than 20 cm; some very small species are delicate inhabitants of the plankton.

Family Feeding

Carnivores - known to feed on small fishes and crustaceans. Species of small genera such as Cyclothone, feed mostly on small pelagic crustaceans such as copepods. Larger species feed on larger crustaceans and small fishes. Some species also feed on salps and small jellyfishes.

Family Reproduction

Many species are sexually dimorphic and/or hermaphroditic. Little is known of eggs or larvae, as species identities are poorly known and larvae are easily confused with those of phosichthids and sternoptychids.